At Which Mean Glandular Dose Does the Benefit of Breast Cancer Deaths Averted Equal the Risk of Lives Lost to Screening From Radiation-induced Malignancy for Mammography With and Without Tomosynthesis?

Objective To estimate benefit-to-radiation-risk mean glandular dose (MGD) equivalence values for screening mammography, defined as the yearly MGD (over a 10-year period) at which the estimated benefit of mammography in terms of deaths averted equals the estimated risk of lives lost to screening due to radiation exposure (a benefit-to-risk ratio of 1). Methods Benefit-to-risk ratios were calculated as the ratio of breast cancer deaths averted and lives lost to screening over 10-year intervals starting at age 40 for mammography and tomosynthesis using previously published methodology. The MGD values at which estimated benefit equals risk were tabulated. Results The MGD values at which benefit-to-risk equivalence points were met for digital screening mammography are 63 milligray (mGy) (ages 40–49), 88 mGy (ages 50–59), 176 mGy (ages 60–69), and 336 mGy (ages 70–79). The MGD values that met benefit-to-risk equivalence for screening tomosynthesis plus digital mammography or synthetic mammography are 80 mGy (ages 40–49), 111 mGy (ages 50–59), 224 mGy (ages 60–69), and 427 mGy (ages 70–79). Conclusion Cutoff MGD values at which the estimated benefit from screening equals the estimated risk are well above standard screening MGD exposures. Care is necessary to ensure that threshold values are not exceeded during a screening exam, particularly for women ages 40–49 years old when using digital mammography plus tomosynthesis (due to an approximate doubling of dose per exam that will more readily exceed cutoff MGD values) and when many additional views are obtained.

Estimates of the Incidence of Crack Cocaine Use in Those Likely to Attend Treatment in the English Population, 2005–2018

<b><i>Background:</i></b> Public health bodies in the UK, and elsewhere, have expressed concern over the wider social and economic impact of crack cocaine use on society. <b><i>Objective:</i></b> The aim of the study was to use English substance misuse treatment data to estimate the incidence of crack cocaine use in the population who are expected to present to treatment with crack cocaine as the primary substance. <b><i>Method:</i></b> Known year of first crack-related treatment demand and age of first use of crack were combined to provide the distribution of lag to treatment for each year of onset. The resulting combined lag distribution was used to estimate the proportion of incident crack cocaine users who will have presented in a given year and, from that, the total number who will have started in that year. <b><i>Results:</i></b> Our estimates identified an approximate doubling in incidence between 2012 and 2016, following a decrease up to 2012. <b><i>Conclusion:</i></b> This represents an increase in treatment demand that is likely to continue for a number of years.

Exploring effects of intermittent light upon visible light promoted water oxidations

Illumination of visible light photocatalytic water oxidations using continuous or intermittent light was investigated using a range of earth abundant metal oxides. Brief light cessations allowed reduced light harvester degradation and gave an approximate doubling of yield and reaction rate.

Latin American Cities in the Eighteenth Century: A Sketch

In Latin America the eighteenth century was a time of approximate doubling of the population and considerable economic development and reorientation of the economy. Urban settlement reflected these changes. The bulk of urban growth was by replication of existing patterns into areas of new settlement. Some expansion of older cities and heightening of urban functions took place. In the reordering of regional economies, Buenos Aires, Havana, and Rio de Janeiro profited; Lima failed to prosper. Within existing and new cities, much building replaced older structures in more durable materials, and, in the largest, multi-family, multi-storied structures appeared. Following developments in Europe, beginnings were made in paving streets, providing lighting, installing drains, and so-forth. In similar wise, administration adopted new forms and social welfare was reorganized for more efficient response to natural disasters. Cultural models, copied from Europe, even included the beginning of cafés.

Identification and Detection of Phytophthora: Reviewing Our Progress, Identifying Our Needs

With the increased attention given to the genus Phytophthora in the last decade in response to the ecological and economic impact of several invasive species (such as P. ramorum, P. kernoviae, and P. alni), there has been a significant increase in the number of described species. In part, this is due to the extensive surveys in historically underexplored ecosystems (e.g., forest and stream ecosystems) undertaken to determine the spread of invasive species and the involvement of Phytophthora species in forest decline worldwide (e.g., oak decline). The past decade has seen an approximate doubling in the number of described species within the genus Phytophthora, and the number will likely continue to increase as more surveys are completed and greater attention is devoted to clarifying phylogenetic relationships and delineating boundaries in species complexes. The development of molecular resources, the availability of credible sequence databases to simplify identification of new species, and the sequencing of several genomes have provided a solid framework to gain a better understanding of the biology, diversity, and taxonomic relationships within the genus. This information is much needed considering the impact invasive or exotic Phytophthora species have had on natural ecosystems and the regulatory issues associated with their management. While this work is improving our ability to identify species based on phylogenetic grouping, it has also revealed that the genus has a much greater diversity than previously appreciated.

Differential response of wheat to retained crop stubbles. II. Other factors influencing allelopathic potential; intraspecific variation, soil type and stubble quantity

The allelopathic potential of the unweathered stubble of field-grown sorghum and sunflower was examined under controlled conditions in a series of glasshouse experiments. Wheat emergence was significantly inhibited in the presence of stubble from the eleven sorghum, and ten of the twelve sunflower cultivars tested. Inhibition of wheat emergence in the presence of sorghum stubbles ranged from 10 to 31%, and in the presence of sunflower stubbles from 4 to 33%, demonstrating a high degree of intraspecific variation in allelopathic potential. Many of the wheat seedlings emerging in stubble treatments exhibited an abnormal geotropic response. A threefold increase in stubble quantity, from 0.5 to 1.5% w/w soil, resulted in an approximate doubling of phytotoxicity. Wheat emergence was significantly reduced when stubble was incorporated into all three soils tested, with greater inhibition recorded in chocolate soil and a 50: 50 chocolate soi1:sand mixture than in sand. The choice of crop cultivar and the management of stubble quantity, especially in harvester trails, have important implications for the minimization of negative allelopathic effects in stubble retention systems.

Pulsed transmission of Pseudodiplorchis americanus (Monogenea) between desert hosts (Scaphiopus couchii)

SummaryTransmission of the monogenean Pseudodiplorchis americanus is restricted to the brief period when its host, the desert toad Scaphiopus couchii enters temporary water to breed. This study followed parasite recruitment into one host population in Arizona, USA, during the spawning season (July). Torrential rainfall triggered 3 successive assemblies. Amongst males, which may enter each assembly, the 3 pulses of invasion led to an approximate doubling of mean worm burdens at each exposure, culminating in 100% prevalence and a mean intensity of over 100 larvae/host. Females, which generally enter only one assembly, acquired a mean of about 40 larvae/host. Each exposure is limited to a maximum of 7 h by strictly nocturnal host activity, and the force of infection increased exponentially: around 10% of recruitment occurred in the first 3 h, and more than 30% in the last 1 h. Correlation of recruitment into males with parasite reproductive potential suggests that individual oncomiracidia had a 30% chance of invasion. Although invasion of the desert host relies on an aquatic infective stage, host behaviour ensures that targets are concentrated in space and time, and the parasite's annual reproductive output is synchronized with a period of host vulnerability totalling less than 24 h/year.

Oribatid mite fossils from a terrestrial Devonian deposit near Gilboa, New York

Fourteen oribatid mite fossils have been recovered from a terrestrial Devonian deposit near Gilboa, New York; they allow an approximate doubling of the known age of the group. Two species are represented by specimens complete enough to allow descriptions. Protochthonius gilboa n. gen. and sp. is the earliest derivative known member of the Enarthronota, and comprises the monobasic new family Protochthoniidae. Devonacarus sellnicki n. gen. and sp. also represents a monobasic new family, Devonacaridae; it may also be an early derivative enarthronote mite, but its relationships are uncertain. Two other species are represented at the site, but meaningful descriptions are not possible with available material.

RELATIONSHIP BETWEEN HAEMORRHAGIC AND LIPASE-RET EASING PROPERTIES OF HEPARIN AND LMV HEPARIN

In a preliminary study, a good correlation (r = 0.97) was noted between the relative abilities of an unfractionated heparin, a LMW heparin, pentosan poly sulphate and dermatan sulphate to prolong the template bleeding time in rabbits and their lipase-releasing potencies. In the present study, we have measured the prolongation of both the template and transection bleeding times in groups of 5 rats given i.v. injections of 0.75 mg/kg of two different unfractionated heparins (UEH), A and B, three different LMW heparins, X, Y and Z, and a heparan sulphate, HS. Lipase release was measured in plasma samples from different groups of 5 rats, using a tritiated triolein method.UFH A had the most haemorrhagic effect, with an approximate doubling of both template and transection bleeding times and was also the most potent lipase-releaser, giving an average lipase level of 1126 mu/ml. UFH B had no significant effect on the template bleeding time, but did prolong the transection time; its lipase releasing potency was 70% of UFH A. IMW heparin X had no effect on template or transection bleeding time and released only 40% lipase compared with UEH A. LMW heparins Y and Z did not affect the template bleeding time but did prolong the transection time; they released more lipase (60%) than LMW heparin X. Correlation coefficients with lipase release were 0.97 for the template bleeding time and 0.69 for the transection bleeding time. HS released only 7% lipase but gave significant prolongations of both bleeding times.These results confirm a strong positive correlation between the haemorrhagic and lipase releasing properties of heparin and LMW heparin, suggesting very similar structural requirements for the two biological activities. This correlation exists also for dermatan sulphate and pentosan polysulphate, but not for the heparan sulphate sample tested.

Induction of haem synthesis in Hep G2 human hepatoma cells by dimethyl sulphoxide. A transcriptionally activated event

Exposure of cultured human hepatoma cells (Hep G2) to medium containing 2% (v/v) dimethyl sulphoxide resulted in an approximate doubling in the activity of delta-aminolaevulinate dehydratase, an increase in the haem content and a decreased growth rate; induced enzyme activity was decrease by 50% after treatment with alpha-amanitin. The findings are strikingly similar to those seen in murine Friend-virus-transformed erythroleukaemia cells.